Weapon and Armor
Proficiency:

A barbarian is proficient with all simple and martial weapons, light
and medium armor, and shields.

Rage (Ex):

The
barbarian is capable of flying into a rage. By doing so, they get a +2
bonus to Strength and Constitution. The increase in Constitution
increases the barbarian’s hit points by 2 points per level, but these
hit points go away at the end of the rage when their Constitution score
drops back to normal. When ending a rage, if the loss of hit points
from this would kill the barbarian, they instead have -9 hitpoints and
are automatically stabilized.

While raging, a barbarian cannot
use any Charisma-, Dexterity-, or Intelligence-based skills except for
Intimidate, nor may they cast any spells. The rage lasts for a number
of rounds equal to the character’s (newly improved) Constitution score.
A barbarian may prematurely end their rage.

A barbarian can fly
into a rage only once per encounter. At 1st level, they can use their
rage ability once per day. At 4th level and every three levels
thereafter, they can use it one additional time per day (to a maximum
of seven times per day at 19th level). Entering a rage takes no time
itself, but a barbarian can do it only during their action, not in
response to someone else’s action.

Fast Movement
(Ex):

Barbarians are very fleet of foot. Starting at second level, their land
speed is increased by 10 feet per round. At twelfth level, this
increases to 20 feet per round.

Mass Fright (Ex):

At level 3, barbarians get the skill trick Mass Fright for free.

Fear No Man (Ex):

Starting at level 3, barbarians are immune to fear.

Damage Reduction
(Ex):

At 5th level, a barbarian gains Damage Reduction. Subtract 1 from the
damage the barbarian takes each time they are dealt damage. At 7th
level,
and every three barbarian levels thereafter, this damage reduction
rises by 2 points. Damage reduction can reduce damage to 0 but not
below 0.